accretion disk

noun

variants or less commonly accretion disc

plural accretion disks also accretion discs

: a disk of usually gaseous matter surrounding a massive celestial object (such as a black hole) in which the matter gradually spirals in toward and accretes onto the object as a result of gravitational attraction

Evans' team studied a supermassive black hole with jets 800 million light-years away named 3C 33. They never found an expected X-ray pattern … which results from light reflecting off the accretion disk.

—Bill Andrews

Most other moons are either captured planetesimals, or they formed along with the planet in a common accretion disc.

—Daniel Herwartz, et al.

Examples of accretion disk in a Sentence

Recent Examples on the Web

Following this investigation, the team determined the rate at which gas was flowing from the accretion disk to this supermassive black hole had been cut by around 98% over the course of just seven years. —Robert Lea, Space.com, 8 Apr. 2026

Some of the stellar guts failed to escape and fell back toward the newborn magnetar, forming a small accretion disk around it. —Jacek Krywko, ArsTechnica, 13 Mar. 2026

Farah’s model for SN 2024afav involves material from the explosion falling inward toward the magnetar and forming what’s known as an accretion disk. —Andrew Paul, Popular Science, 11 Mar. 2026

There, two supermassive black holes and their surrounding accretion disks are locked in a dance that will eventually merge them into one. —Liz Kruesi, Quanta Magazine, 2 Feb. 2026

Word History

First Known Use

1972, in the meaning defined above

Rhymes for accretion disk

• videodisc
• basilisk
• bisque
• brisk
• disc
• fisc
• fisk
• frisk
• risk
• whisk